Could you tell me if there is any difference in meaning between do something in one's own time and do something on one's own time? For example, in the 12th episode of the 10th season of Friends, Monica said the latter. Here is the context:
Mike: Do I have a minute to go to the bathroom?
Monica: You had a bathroom break at 2030. Pee on your own time, Mike! (to Phoebe and Mike). Now, in regard to the toast, okay, you wanna keep them short, nothing kills a rehearsal dinner like long speeches. Okay. You just get in, do your thing and get out!
Would the meaning somehow change if she said in your own time?